Randomized generation of text, subject to syntactic constraints, has potentially broad applications, including (but certainly not limited to) the generation of input test cases for various types of software. Various programs supporting syntactically-rich input, in particular, may benefit from testing with automatically-generated inputs that obey context-free syntactic constraints but which are otherwise randomized. The m4r examples page provides an illustration in which an m4r script is used to test a subset of the input language supported by the UNIX bc(1) bench calculator program.